Here are some web sites that will help you with your problems.
http://water.epa.gov/polwaste/nps/runoff.cfm http://www.doityourself.com/stry/water-erosion-and-how-to-avoid-itWater causes erosion by hitting the sides. The water would heat up and go faster and then it would hit the sides and make it longer. Water erosion could make a under water cave. The way it forms is that the current starts to move faster and faster as it heats up. while it moves fast it will scrape away the minerals away and it will start to form erosion. It doesn't take over night for erosion to form. If it is big erosion it could take 40 years but if it is little it could take about 5 years. Water erosion is helpful at times because it could make big rivers for boats or ponds for fish. But you have to remember that erosion takes a lot of time. Canyons are mostly formed by glaciers and water that just sits there.The way the water falls will form is exactly erosion. The rain water will build up from snow or rain then the water will start to move and take up the minerals. Then The Rock or dirt may collapse . The churning water will then start to churn and start to dig more and more until it turn's into a pond or lake. Water erosion will destroy houses and landscapes. The rain will erode the soil and that will cause maybe a mud slide.
http://water.epa.gov/polwaste/nps/runoff.cfm
http://www.doityourself.com/stry/water-erosion-and-how-to-avoid-itWater causes erosion by hitting the sides. The water would heat up and go faster and then it would hit the sides and make it longer. Water erosion could make a under water cave. The way it forms is that the current starts to move faster and faster as it heats up. while it moves fast it will scrape away the minerals away and it will start to form erosion. It doesn't take over night for erosion to form. If it is big erosion it could take 40 years but if it is little it could take about 5 years. Water erosion is helpful at times because it could make big rivers for boats or ponds for fish. But you have to remember that erosion takes a lot of time. Canyons are mostly formed by glaciers and water that just sits there.The way the water falls will form is exactly erosion. The rain water will build up from snow or rain then the water will start to move and take up the minerals. Then The Rock or dirt may collapse . The churning water will then start to churn and start to dig more and more until it turn's into a pond or lake. Water erosion will destroy houses and landscapes. The rain will erode the soil and that will cause maybe a mud slide.